Island



(No Model!) I 0. 1). ROGERS.

THRBADING- DIE.

No. 255,817. Patented Apr. 4,1882.

FIG-Z.-

WITNESSEE- INVENTDR.

n. PEIERi PnmLinm m r-Qr. Washington, D. c.

I UNITED STATES PATENT OFFICE.

CHARLES 1). ROGERS, OF'PROVIDENGE, RHODE ISLAND, ASSIGNOR TO THE eAMERICAN SGREVV COMPANY, OF SAME PLACE.

THREADlNG-DIE.

SPECIFICATION forming part of Letters Patent No. 255,817, dated April 4,1882.

' Application filed October 1-2, 1881. (No model.)

To all whom it may concern:

Be it known that I, OHAnLEs D. ROGERS, otthe city and countyofProvidence, and State of Rhode Island, have invented a new and usefulImprovement in Threading-Dies; and I do hereby declare that thefollowing specification, taken in connection with the accompanyingdrawings, forming a part of the same, is afull, clear, and exactdescription thereof.

' My invention relates to that variety of dies for threadingscrew-blanks, boltblanks, &c., in which the cutters are adjustable, inorder that the gage of cut may be maintained as the cutters wear away,and in order that blanks of difi'erent sizes within certain limits maybe threaded with one and the same die.

My improvement consists in mounting the cutters on the face or extremeend of the diehub and in radial grooves of a dovetail or equivalentshape,which holdthecutters against displacement or removal in adirection lengthwise of the die-hub, and combining with the die-hub andcutters asingle screw-sleeve which is threaded to engage the hub and hasa beveled month which supports the correspondin gly-beveled rear ends ofthe cutters and atfords a means for their adjustment.

My improvement also consists in constructing the die so that the chipswill be readily discharged therefrom during the operation of threading.

Referring to the drawings, Figure l represents a front view of myimproved die. Fig. 2 shows a section of the same on linear w, and Fig. 3represents a side view of the hub with the cutters mounted therein.

A is the hollow die-hub, which is provided witha female screw-thread, a,as shown in Fig. 2, to enable it to be attached to a revolving spindle.The face A of the hub is centrally perforated, and is provided withradial grooves of a dovetail or equivalent shape to receive and holdagainst displacementin a direction length wise of the die-hub thecutters B, which may be two or more in number and are of a shape to fitsaid grooves. As shown in Figs. 2 and 3, the main portion of theexterior of the hub is threaded andis engaged by a surrounding sleeve,0. The mouth 0 of this sleeve is beveled, as shown in Fig. 2, and therear ends of the cutters are also beveled to fit said mouth. From thefact that the cutters are held in the dovetail grooves in the face ofthe die-hub against lateral displacement and have broad bearings uponthe sleeve 0 to prevent radial displacement, the die has all theadvantages of one that is solid.

The cutters B are simultaneously adjusted to produce a thread of thedesired gage by a movement of the sleeve (1. As this sleeve is movedforward by rotation on the hub A the inner ends of the cutters arebrought nearer together, and when the sleeve is moved rcar ward thecutters may be separated. A means is thus provided whereby any gagewithin cer- 6 5 tain limits may be secured and maintained.

For conveniently moving the sleeve 0 it is preferably provided with oneor more cavities, c, Fig. 2, for the reception of a lever to aid inturning the sleeve; and to prevent the sleeve 0 from being accidentallyturned it is provided with a set-screw, D, which bears upon a plug, 01,fitted to engage the hub A, as shown in Fig. 2. For the purpose ofreceiving the chips and 7 5 dirt which would tend to clog the die thehub is provided with an interior chamber, E, from which discharge-ductse 0 lead outward.

From the foregoing description it will be understood that my improveddie is practically solid, since the cutters are rigidly held againstdisplacement when performing their ofiice. It will also be seen that itpossesses advantages over a solid die in that the cutters can be adjusted to gage as they wear away and new cut 8 ters can be substitutedat comparatively small expense. The die can also be arranged to threadblanks of different diameters within certain limits. By mounting thecutters in grooves on the end or face of the die-hub, as shown, 0 theblanks can be threaded close up under the head, which is very desirablein certain classes of screws. And, finally, the chips and dirt whichwould tend to clog the die are discharged clear of the cutters, therebyallowing the die 9 5 to produce superior results.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. A threading-die composed of a threaded hub having radial grooves,constructed as described, on its face or extreme end, cutters mounted insaid grooves and retained therein against movement lengthwise of thehub, and a single screw-sleeve which engages the threaded portion of thehub and has a beveled mouth which engages the beveled rear ends of thecutters, substantially as set forth.

2. As an improved article of manufacture, a threading-die having aninterior chamber and ducts leading outward therefrom, whereby the chips,&c., which would tend to clog the die may be discharged, substantiallyas set forth.

3. As an improved article of manufacture, a threading-die composed of achambered hub having dovetail grooves in its face for the reception ofcutters, cutters mounted in said grooves, a sleeve mounted on said huband adapted to adjust and hold the cutters to gage, means for securingsaid sleeve in position, and duets leading outward from the hamber inthe hub, substantially as and for the purposes specified.

- CHARLES D. ROGERS. Witnesses: W. H. THURSTON, I. KNIGHT.

